Assets (Liabilities) Measured at Fair Value on a Recurring Basis | | | | | | | | | | | | | | | | (in millions) | September 30,
2020 | Level 1 | Level 2 | Level 3 | | Cash equivalents | $ | 13,554 | | $ | 13,554 | | $ | — | | $ | — | | | Restricted cash equivalents | 1,868 | | 1,868 | | — | | — | | | Short-term investments | | | | | | U.S. Government securities | 5,048 | | 3,694 | | 1,354 | | — | | | Long-term investments | 1,310 | | 846 | | 230 | | 234 | | | Hedge derivatives, net | | | | | | Fuel hedge contracts | (3) | | — | | (3) | | — | | | Interest rate contracts | 25 | | — | | 25 | | — | | | Foreign currency exchange contracts | (2) | | — | | (2) | | — | |
| | | | | | | | | | | | | (in millions) | December 31,
2019 | Level 1 | Level 2 | | Cash equivalents | $ | 586 | | $ | 586 | | $ | — | | | Restricted cash equivalents | 847 | | 847 | | — | | |
| Long-term investments | 1,099 | | 881 | | 218 | | | Hedge derivatives, net | | | | | Fuel hedge contracts | 1 | | (1) | | 2 | | | Interest rate contracts | 61 | | — | | 61 | | | Foreign currency exchange contracts | 6 | | — | | 6 | |
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